The phenomena of glare or halo occurs when, after an operation of refraction-correction such as lasik or lasek, an iris of an eye excessively contracts and a pupil is enlarged that external light comes in through wider area than the operated cornea area. In this case, a focus of an image of objects is formed in front of a retina and the patient feels the glare or halo spread out from the object when he or she sees the objects. FIG. 1 shows the structure of an eye 100 in which the phenomena of the glare occurs. The operation of refraction-correction such as lasik or lasek is to cut off a portion of the cornea by means of laser in order to adjust the refractive index so that the object image is exactly focused on the retina. With reference to FIG. 1, by the operation, the cornea is cut off by the area of the shaded portion 23 so that the object focus f1 is exactly formed on the retina 40. Since the external light comes in through the cut off area of retina to pass lens 30, the object focus f1 is exactly formed on the retina 40. The track of the light in this case is shown by reference number 50. However, in some cases, the iris 10 which adjusts the lens 30 excessively contracts and the pupil is enlarged. In that case, as indicated by the dotted line of reference number 60, the external light comes in through wider area than the operated cornea area and, as a result, the focus f2 of the object image is formed in front of the retina 40. Patients who have this phenomena feel glare or halo spread out from the objects when they see the objects. This phenomena may cause troubles and inconveniences. Especially, the patient has a difficulty in driving at night.
Conventionally, an ophthalmologist treats the patient in such a way that the doctor asks the patient some questions about the symptoms and hears the answers. Based on the answer the doctor analyzes the condition of illness and the degree of remedy. For instance, the doctor asks how much glare the patient feels when seeing a street light at night and checks the condition of illness by the answer.
Beyond the above conventional way, the present invention provides an apparatus which can quantitatively analyze the phenomena of glare and the method for the same.
The purpose of the present invention is to provide an apparatus which can quantitatively analyze the phenomena of glare and the method for the same.
Quantitatively analysis method for the phenomena of glare according to the present invention includes the steps of reading light source picture information from a memory part and displaying the light source picture on a display part, reading position information of the circumference of the glare when a patient suffering from the phenomena of glare draws circumference line of the glare by means of a pointing device and calculating area of circumference of glare and outputting the calculated area. The output of the area indicates the condition of illness and the degree of remedy of the patient.
It is preferable that the quantitatively analysis method for the phenomena of glare further includes the step of producing circumference display information by using the position information of the circumference of the glare and displaying circumference on the light source picture on the display part according to the circumference display information. This display visually enhances the understanding of the condition of illness and the degree of remedy. Especially, the step of calculating area of circumference of glare may includes the steps of calculating distances between points of the circumference which are symmetric each other with respect to a central point of the light source, producing average value of the distances and calculating area of circle by using the average distance value as a diameter.
The present invention may be embodied by a computer readable storage medium containing a computer readable program to make computer execute the described above steps.
Quantitatively analysis apparatus for the phenomena of glare according to the present invention includes means for memorizing light source picture information, means for reading the light source picture information and displaying the light source picture on a display part, means for inputting position information of circumference, means for calculating area of the circumference of glare by using the position information of the circumference of glare and means for outputting the calculated area.
Preferably, the quantitatively analysis apparatus for the phenomena of glare further includes means for producing circumference display information by using the position information of the circumference of the glare and means for displaying circumference on the light source picture on the display part according to the circumference display information. Especially, the means for calculating area of circumference of glare may include means for calculating distances between points of the circumference which are symmetric each other with respect to a central point of the light source, means for producing average value of the distances and means for calculating area of circle by using the average distance value as a diameter.